How Do Wetsuits Work? Do They Keep You Warm and Dry?

A wetsuit keeps you warm by wrapping you in neoprene, a rubber foam filled with millions of tiny gas bubbles that slow the loss of body heat to the water. A thin film of water still gets inside. Your body warms it, and a snug fit stops it from being flushed out and replaced. So a wetsuit keeps you warmer, not dry, and it helps you float.

That is the short version. The rest of this guide covers how warm a wetsuit actually keeps you, why it makes you more buoyant, what it is made of, what one costs, and how to look after it.

We fit and rent triathlon wetsuits at our shop in Arvada, so the examples lean toward open water swimming. The physics is the same whether you surf, dive, paddle, or race.

How Does a Wetsuit Work?

A wetsuit does three jobs at once: it insulates, it seals, and it floats.

1. Insulation. Neoprene is a synthetic rubber foamed with tiny sealed gas bubbles, mostly nitrogen. Gas is a poor conductor of heat, so those bubbles form a barrier between your skin and the water. Thicker neoprene means more insulation.
2. Seal. The suit fits like a second skin. A little water seeps in at the neck, wrists, ankles, and zipper, and your body warms it within a minute or two. A close fit holds that warmed water in place.
3. Buoyancy. The same gas bubbles that insulate also make neoprene much lighter than water, which lifts your body toward the surface.

The Myth About the Layer of Water

You will often hear that the thin layer of water inside the suit is what keeps you warm. It is not. Water does not insulate. The neoprene does.

The water inside is only harmless for as long as it stays put. Warm water sitting against your skin costs you nothing. Cold water flushing through costs you heat with every stroke. This is why fit matters more than thickness: a thick suit that gapes at the neck is colder than a thinner suit that seals. If you are not sure what a good seal feels like, our guide to how tight a wetsuit should be walks through the checks we use in the fitting room.

Do Wetsuits Keep You Warm?

Yes. A wetsuit keeps you far warmer than bare skin in the same water. It slows heat loss, it does not stop it, so how warm you stay depends on the water temperature, the suit, and how long you are in.

The reason you need one at all is that water pulls heat from your body roughly 25 times faster than air at the same temperature. That is why 65°F water feels nothing like a 65°F afternoon. Neoprene puts a layer of trapped gas between you and that water.

How Warm Does a Wetsuit Keep You?

For a standard full sleeve triathlon wetsuit, this is a fair guide.

Water temperature	What to expect in a triathlon wetsuit
Below about 56°F	A standard suit is not enough for a long swim. Add a thermal wetsuit, neoprene cap, gloves, and booties, and keep it short.
56 to 65°F	Cold on entry, comfortable once you are moving. A neoprene cap makes a big difference.
65 to 72°F	The sweet spot. Warm enough to relax, cool enough to work hard.
72 to 78°F	A full sleeve suit can run hot at race effort. Sleeveless is more comfortable.
78.1 to 83.9°F	USA Triathlon allows a wetsuit, but you are not eligible for awards.
84°F and above	Wetsuits are not permitted in USA Triathlon races.

A lot of body heat escapes through your head, hands, and feet. In cold water, a neoprene swim cap, hood, or gloves often adds more comfort than a thicker suit. For water in the low 50s, a thermal wetsuit adds a wool-like inner lining that traps extra warmth. blueseventy makes one of the better known versions.

Cold water kit we stock:

If most of your swimming is in warm water, a sleeveless suit such as the blueseventy Reaction Sleeveless (men's, women's) is the more comfortable choice. Above the 78°F limit, a swimskin is legal where a wetsuit is not.

Why You Still Feel Cold for the First Minute

When you first get in, cold water runs into the suit before your body has had time to warm it. That is normal, and it passes.

Get in a few minutes before your start. Let water in at the neck on purpose, float, and swim easy until your breathing settles. A wetsuit will not prevent the gasp you get from cold water on your face in the first few seconds. What it prevents is the slow chill over the next twenty minutes.

Do Wetsuits Keep You Dry?

No. A wetsuit is designed to let a small amount of water in, which is where the name comes from. The neoprene itself is waterproof, but the suit is not sealed at the neck, wrists, ankles, or zipper, so you will be wet underneath. If you need to stay dry, you want a drysuit.

Wetsuit vs Drysuit

	Wetsuit	Drysuit
Keeps you dry	No	Yes, with sealed gaskets at the neck and wrists
How it insulates	Neoprene foam worn against the skin	A waterproof shell over warm layers you wear underneath
Fit	Skin tight	Loose
Buoyancy	Built into the neoprene	Comes from air trapped inside the suit
Best for	Swimming, triathlon, surfing	Kayaking, sailing, paddling, cold water diving
Swimming in it	Built for it	Too baggy to swim well
Cost	About $200 to $1,000	Usually more than a comparable wetsuit

For open water swimming and triathlon, a wetsuit is the right tool. A drysuit is for staying dry on top of the water or deep under it, not for swimming through it.

Do Wetsuits Help You Float?

Yes. Neoprene is full of gas, so it is much less dense than water, and a full wetsuit adds noticeable lift over your whole body. Most swimmers find their hips and legs ride higher, which reduces drag and makes swimming feel easier.

Triathlon wetsuits are designed around this. Thicker panels, up to the 5 mm maximum USA Triathlon allows, sit over the hips and thighs to lift the legs. Thinner, stretchier panels, often around 1.5 to 2 mm, cover the shoulders and arms so you can rotate freely. The result is a body position most of us cannot hold on our own, and it is the main reason nearly everyone swims faster in a wetsuit than without one.

Three things worth knowing:

• It matters more in fresh water. Salt water is denser and holds you up. A Colorado reservoir does not, so the lift from a wetsuit is more noticeable here than in an ocean race.
• It helps weaker swimmers most. If your legs sink, the suit does what your kick cannot.
• It is not a life jacket. A wetsuit will not hold your face out of the water if you get into trouble. In open water, swim with other people.

What Are Wetsuits Made Of?

Wetsuits are made of neoprene, a synthetic rubber (polychloroprene) that is foamed so it is full of sealed gas bubbles. The rubber is made from either petroleum or limestone. Many triathlon wetsuits, including the blueseventy and SUMARPO suits we carry, use limestone-based Yamamoto neoprene from Japan, which is light, stretchy, and very buoyant.

A triathlon wetsuit has four parts worth knowing about:

• Neoprene panels in different thicknesses. Thick where you need lift and warmth, thin where you need to move.
• A smooth outer coating. The slick rubber skin lets water slide past. It is also the part that fingernails tear.
• A fabric lining. A thin stretch jersey on the inside that lets the suit slide on and off.
• Glued and stitched seams. Panels are glued together, then stitched without piercing all the way through, so the seams do not leak.

Why Are Wetsuits Black?

Because carbon black is mixed into the rubber. It makes neoprene stronger and far more resistant to sunlight, and it happens to be black. Black also absorbs heat from the sun, which is a small bonus on a cold morning.

Triathlon Wetsuit vs Surf Wetsuit

They look similar on a rack and behave very differently in the water.

	Triathlon or swimming wetsuit	Surf wetsuit
Built for	Swimming fast, lying flat	Sitting on a board, paddling, and falling off
Outer surface	Smooth, slick coating for low drag	Fabric faced for toughness
Shoulders	Very thin and flexible for a full stroke	Thicker, with less stretch overhead
Buoyancy	Tuned, with extra lift at the hips and legs	Even, chosen for warmth
Getting it off	Designed to come off in seconds	Not a priority
Durability	More delicate, handle with fingertips	Built to be abused

You can race a triathlon in a surf wetsuit as long as no part of it is thicker than 5 mm. You will work harder through the shoulders and swim slower. If you are racing once and do not own a swim wetsuit, it makes more sense to rent one for five days.

How Much Does a Wetsuit Cost?

A new triathlon wetsuit costs roughly $200 to $1,000. As of October 2026, the swim and triathlon suits on our shelves run from about $200 to $995, and a five day rental is $60.

Level	Typical price	What you get
Entry	About $200 to $330	Thicker, less stretchy neoprene. Warm, buoyant, and durable. Everything a first season needs.
Mid range	About $370 to $560	Thinner shoulder panels, better tuned buoyancy, faster removal. The best value if you race a few times a year.
Top end	About $680 to $1,000	The lightest and most flexible neoprene and the most refined fit. Worth it for strong swimmers chasing time.
Rental	$60 for five days	A proper swim wetsuit for one race or a trial swim.

One wetsuit at each level, in men's and women's cuts:

Three honest notes on spending:

• Fit beats price. A $250 suit that fits will be warmer and faster than a $900 suit that does not. Check the wetsuit size chart for your brand, because sizes do not match across brands.
• Sleeveless costs less. The sleeveless version of a suit is usually cheaper than the full sleeve version and is more comfortable in warm water. Full sleeve is warmer and faster.
• Last season's suit is the same suit. Neoprene does not change much year to year. Our Orca Clearance section is the first place to look for a deal.

You can see every suit and current price in men's wetsuits and women's wetsuits, including Orca, blueseventy, TYR, and SUMARPO.

How to Wash, Dry, and Store a Wetsuit

Rinse it in cool fresh water after every swim, hand wash it with wetsuit shampoo every few weeks, dry it inside out in the shade, and store it flat or on a wide hanger. Never use hot water, a washing machine, a dryer, or direct sun.

When	What to do
After every swim	Rinse inside and out with cool fresh water. That includes pool swims, because chlorine is hard on neoprene. Hang it folded at the waist over a wide hanger or rail, inside out, in the shade. Turn it right side out once the inside is dry.
Every few weeks	Hand wash in a tub of cool water with a wetsuit shampoo. Knead it through gently, then rinse until the water runs clear.
End of the season	Wash it, dry it completely, and store it flat or on a thick hanger somewhere cool, dark, and dry. Do not fold it. Creases become permanent.
Never	Hot water, washing machine, dryer, bleach, iron, wire hangers, direct sunlight, or a hot car.

Two Colorado notes. Sunlight at altitude is stronger and breaks neoprene down faster, and our dry air dries a suit quickly anyway, so the shade costs you nothing. And the trunk of a car in a reservoir parking lot in July is the fastest way to ruin one.

Small fingernail nicks in the outer skin are normal and easy to fix at home with Aquaseal neoprene cement. For lubricant, use a product made for wetsuits such as Body Glide, not petroleum jelly, which damages neoprene over time.

A simple wetsuit care kit:

Looked after this way, a triathlon wetsuit should last several seasons of regular use.

Do You Need a Wetsuit in Colorado?

For open water, almost always. Front Range reservoirs run roughly in the high 50s in May, the high 60s in June, the mid to high 70s in July and August, and back into the low 70s by September. That puts nearly every Colorado race under the 78°F wetsuit limit, and most of them in water where a suit is about comfort and not only speed. Add fresh water, which gives you less natural lift than the ocean, and you get more out of a wetsuit here than almost anywhere.

The off-season is the best time to sort one out. There is no race next weekend forcing a decision, there is time to try more than one size, and last season's models are marked down.

If you are planning a first race, our guide to sprint triathlon distances covers what you are training for, the 2027 Colorado triathlon race calendar will help you pick one, and what to wear under a wetsuit covers getting the thing on.

Frequently Asked Questions

Do wetsuits keep you warm?

Yes. Neoprene is a rubber foam full of tiny gas bubbles that slow the loss of body heat to the water. A wetsuit does not make heat, it keeps more of yours. In very cold water you will still get cold over time.

Do wetsuits keep you dry?

No. A small amount of water gets in at the neck, wrists, ankles, and zipper, and your body warms it. If you need to stay dry, you need a drysuit.

Do wetsuits help you float?

Yes. Neoprene is much less dense than water, so a wetsuit lifts your body, especially your hips and legs. That is why most people swim faster in one. It is not a substitute for a life jacket.

What are wetsuits made of?

Neoprene, a synthetic rubber foam made from petroleum or limestone, with a smooth outer coating and a thin fabric lining. The panels are glued and stitched together in different thicknesses.

How much does a wetsuit cost?

A new triathlon wetsuit runs from about $200 for an entry level suit to about $1,000 for a top end one. Renting costs $60 for five days at our shop.

Can you put a wetsuit in the washing machine or dryer?

No. Heat and agitation damage neoprene and its seams. Hand wash in cool water with wetsuit shampoo and hang it to dry in the shade.

How long does a wetsuit last?

With a rinse after every swim, shade drying, and flat or wide hanger storage, a triathlon wetsuit should last several seasons of regular use. Heat, sun, and fingernails are what shorten that.

Want to Feel the Difference Before You Buy?

Come by the shop at 14715 W 64th Ave, Unit D in Arvada and try a few on. We carry Orca, blueseventy, TYR, and SUMARPO in men's and women's cuts, full sleeve and sleeveless, and we rent by the five day block. We will get you into the right size and show you how to look after it. Check our store hours and location before you head over.

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